Electrostatic actuators operate via an attractive force that is created when charges of opposite polarity are separated by a distance, in accordance with Coulomb's law. When a voltage is applied across two electrodes separated by a distance, opposite charges are generated on the electrodes, thereby creating an attractive force. The attractive force is proportional to quantity of the charge on the electrodes and inversely proportional to the square of the distance between the charged electrodes. As distance between the charged electrodes is decreased, the force is increased.
Using known electrostatic actuators in user interface implementations with touch screen displays, for example, may be limited in terms or providing satisfactory haptic feedback to the user due to the large mass of the touch screen display (e.g. 600-800 grams) and the high voltage (e.g. >3,000 Volts) that may be needed by an electrostatic actuator that has the same surface area as the touch screen display.